[Increase of blood levels of creatine kinase following intramuscular injection].

BACKGROUND

To analyze the effect of intramuscular injections of drugs on serum creatine kinase (CK) and to evaluate the possible existence of factors that lead to predict the probability of appearance of serum CK increase after injection.

PATIENTS, MATERIAL AND METHODS: One hundred and seventy six consecutive patients admitted to a short-term medical ward for non-cardiac reasons who had normal serum CK levels, were selected for the study. 120 of them, selected for random allocation, received a single 0 multiple injections of drugs (with broad use in emergency medicine) in the gluteal muscle (group IM). The remaining 56 patients were the group control, in all the cases serum CK was measured at 0, 6, 12, 24 and 48 h since the admission.

RESULTS

A significant elevation of serum CK levels occurred in 58.3% cases of group IM. The higher ratio of cases with increment of CK levels was observed after the injection of chlorpromazine (100%), followed of diclofenac (74.2%), metamizol (60%) and multiple drugs (60%). In most cases the highest increment was observed at 12 h after injection. A tenfold increase in serum CK level was found after intramuscular injection of diclofenac. There were significant differences between the elevation or not of serum CK and the type of drug administered (p < 0.05), sex (p < 0.05), and the solvent of the drug injected (p < 0.05). A higher probability of serum CK elevation was observed in men (p = 0.009) and when the solvent of the drug injected was ethanol (p = 0.0499).

CONCLUSIONS

There is a high probability of serum CK increment after intramuscular injection of drugs. The sex and the solvent of the drug injected have influence on this probability. The magnitude of this enzymatic increment depends on the kind of the drug injected, being non steroidal anti-inflammatory drugs those higher serum CK increment have been produced in the present study.